FIX: Trying to fix CI...

CMakeLists.txt

@@ -11,8 +11,10 @@ message("Using CMake ${CMAKE_VERSION}")
 # Set a flag for parallel compilation #
 #-------------------------------------#
 set(ENV{PARALLEL_BUILD_FLAG} "-j")
+set(PARALLEL_BUILD_FLAG $ENV{PARALLEL_BUILD_FLAG})
 if(WIN32)
     set(ENV{PARALLEL_BUILD_FLAG} "/MP")
+    set(PARALLEL_BUILD_FLAG $ENV{PARALLEL_BUILD_FLAG})
 endif()
 
 #------------------------------------------#

DownloadBoost.cmake

@@ -40,7 +40,6 @@ FetchContent_Populate(boost)
 ###############
 # Build Boost #
 ###############
-
 set(BOOTSTRAP_CMD sh bootstrap.sh)
 set(B2_CMD ./b2 ${PARALLEL_BUILD_FLAG}${N_CORES})
 if(WIN32)